Help! Will hydrogen peroxide hurt roots?

[MattE]

Hey all,
I have such a bad fungus Gnat problem i didnt know they liked bonsai soil i thought thwey onlyliked dirt.. i need to kill them off and i read somewhere that hydrogen peroxide 3% dilluted in water will kill them and larva on contact.
what i need to know is how will the effect the roots on my plants ? is this going to kill back my roots or trees at all?
Should i soak the soil down and then rinse it clean after about 10 to 15 min of the solution sitting?
i did search around the site a bit but couldn't find the answers i was looking for.
Species i will be treating are Brazillian rain tree , chinese elm , ficus, serissa, pomegranates, PA ect

Thanks for every and all info

 

[Tums]

Wouldn't do it. Hydrogen peroxide won't distinguish between larvae and plant roots. Try a soil drench insecticide like imidacloprid or BTi or something.

Also what manner of bonsai soil are you using? If it was something entirely inorganic like APL I would be surprised but if there's organic material of any kind, even bark, I've seen them go for it.

 

[MattE]

Wouldn't do it. Hydrogen peroxide won't distinguish between larvae and plant roots. Try a soil drench insecticide like imidacloprid or BTi or something.

Also what manner of bonsai soil are you using? If it was something entirely inorganic like APL I would be surprised but if there's organic material of any kind, even bark, I've seen them go for it.

I have been reading that hydrogen peroxide is ok ish on plants I just wanted to confirm and I use “the bonsai supply “ bonsai soil there is some bark but not much

 

[penumbra]

I have used it multiple times with excellent results to get rid of fungus gnats. I have also saved a couple of ficus that had root rot. I generally use 3% diluted with an equal part of water.

 

[Carol 83]

@penumbra you beat by like one second!

 

[penumbra]

@penumbra you beat by like one second!

You have it all over me in so many ways.

 

[Carol 83]

You have it all over me in so many ways.

Did you see my post, the Wal-mart Valentine's azaleas are back, I didn't forget! Better hurry, our Wal-mart only had a a few.

 

[Michigan Tree Murderer]

Hey all,
I have such a bad fungus Gnat problem i didnt know they liked bonsai soil i thought thwey onlyliked dirt.. i need to kill them off and i read somewhere that hydrogen peroxide 3% dilluted in water will kill them and larva on contact.
what i need to know is how will the effect the roots on my plants ? is this going to kill back my roots or trees at all?
Should i soak the soil down and then rinse it clean after about 10 to 15 min of the solution sitting?
i did search around the site a bit but couldn't find the answers i was looking for.
Species i will be treating are Brazillian rain tree , chinese elm , ficus, serissa, pomegranates, PA ect

Thanks for every and all info

I recently received a shipment of gnats with my last tree and I use these.



Yellow sticky paper. That way you can laugh at their corpses when you throw it away.
Does nothing for the eggs though.

 

[Tums]

I'll definitely defer to firsthand experience then. I remembered reading about poor results treating orchids with h2o2 but maybe woody roots are different.

 

[ShadyStump]

I've accidentally killed trees with alcohol, fertilizer, pesticide, pretty much everything EXCEPT H²O². It's about as safe a soil treatment as you can find, but remember that it can also kill your soil microbiome. That's the number one reason for diluting it. If you're tree is dependent on the mycorrhizae and other microbes, you might see a slight decline some time after treatment, but don't panic as long as you're doing all the rest right. Shouldn't be noticable on tropicals half asleep for winter.
Otherwise, H²O² breaks down as it works into O² and water. Your trees will love it.

 

[Glaucus]

No, it won't damage the roots at the correct dilutions. It also will not kill the gnats very well.
Yellow sticky surfaces (either specific sticky traps or make your own using yellow disposable paper plates with sticky petroleum jelly) will allow you to manage the infestation.
The traps however will never end it because it will never kill the larvae.

To kill the larva you need to but fresh nematodes that infect the gnat larvae. I can check the species for you.
And you need to get them fresh & refrigerated from a reliable source, so they are all still alive when you get them.
This is the only way to kill all of them.

 

[MattE]

Well I used diluted 3% and it definitely cut them down a lot. I found the yellow sticky tape to catch them but it wasn’t enough I needed to get the larva. I’m going to wait it out a couple weeks to a month and treat again.
I didn’t go half and half more like 1 to 3 or 4
I really appreciate everyone’s inputs

 

[Srt8madness]

Did you see my post, the Wal-mart Valentine's azaleas are back, I didn't forget! Better hurry, our Wal-mart only had a a few.

Literally going to Walmart right now to investigate, thanks for the tip!

 

[Michigan Tree Murderer]

Did you see my post, the Wal-mart Valentine's azaleas are back, I didn't forget! Better hurry, our Wal-mart only had a a few.

I only saw two $30 dollar ones in Martha Stewart Pots. Could be another truckload inbound before V-Day, but I didn't even see them in the flyer.

 

[penumbra]

Did you see my post, the Wal-mart Valentine's azaleas are back, I didn't forget! Better hurry, our Wal-mart only had a a few.

I actually picked one up and then left it in my car the night it went down to 12F. The selection was not as good as last years and all 4 of mine from last year are in a cold frame and they look fine.

 

[Carol 83]

I actually picked one up and then left it in my car the night it went down to 12F. The selection was not as good as last years and all 4 of mine from last year are in a cold frame and they look fine.

They only had a few but I still picked up 2. I experimented and put 2 from last year in the garage and kept 2 inside under the lights. The ones in the garage are ok but the ones inside are actively growing and about to bloom again.

 

[canoeguide]

Sprinkle on soil. Stop over watering. Dunzo!

 

[rollwithak]

View attachment 471829
Sprinkle on soil. Stop over watering. Dunzo!

I was getting ready to post these! Works like a charm. Might take a couple treatments. Easy as pie

 

[Glaucus]

View attachment 471829
Sprinkle on soil. Stop over watering. Dunzo!

I tried these as well and it didn't work as well as nematodes. I think there was some effect. The problem is, peroxide and mosquito bits will also kill nematodes. So you can't stack them.

 

[Glaucus]

Also, peroxide likely kills the bacillus thuringiensis in the mosquito bits.